With the latest updates of udev, I am having issues with my XEN server. The latest xen kernel is 2.6.38 and udev seems to require 2.6.39. Shall I block the udev upgrade? Here is the output of the update, I have re-compiled my kernel with DEVTMPFS=y already, I don't know why I aslo get this error, my sources are in /usr/src/linux, but I compile in another folder, as suggested in the xen on gentoo wiki.

Code:

* DEVTMPFS is not set in this kernel. Udev will not run.
* Please check to make sure these options are set correctly.
* Failure to do so may cause unexpected problems.
* Your kernel version (2.6.38-xen) is too old to run udev-197
* It must be at least 2.6.39!
* Could not detect kernel version.
* Please ensure that /data/xen/build/dom0 points to a complete set of Linux sources.
* Unable to calculate Linux Kernel version for build, attempting to use running version
*
* Your running kernel version () is too old
* for this version of udev.
* You must upgrade your kernel or downgrade udev.

Mask if you can then... Else you have to upgrade the kernel to one that has the option - apparently it requires CONFIG_DEVTMPFS, which will break your machine on next boot if it's not enabled (even non-virtual machines and kernels of the proper version).

I just hosed several of my machines because of this..._________________Intel Core i7 2700K@ 4.1GHz/HD3000 graphics/8GB DDR3/180GB SSDWhat am I supposed to be advocating?

Mask if you can then... Else you have to upgrade the kernel to one that has the option - apparently it requires CONFIG_DEVTMPFS, which will break your machine on next boot if it's not enabled (even non-virtual machines and kernels of the proper version).

I just hosed several of my machines because of this...

Thanks a lot. Yes, I messed up some of my machines because of that too!

For now, I masked the udev upgrade, but I hope there will be a better solution. 2.6.38 actually does have the CONFIG_DEVTMPFS option, I recompiled the kernel with it on my xen dom0 and domU but I haven't dared switching.

I have briefly looked for it and did not find how to switch to eudev. I did not see a relevant USE flag in virtual/udev and the Gentoo eudev project page does not say much either. Do you know where I can find more?

I have briefly looked for it and did not find how to switch to eudev. I did not see a relevant USE flag in virtual/udev and the Gentoo eudev project page does not say much either. Do you know where I can find more?

@syl22_00 : Maybe you could just test.
I have been running absolutely troublefree for a week a gentoo-sources and a ck-sources 2.6.38 kernel with udev-197-r3 (udev I had emerged when running a > 2.6.38 kernel)
OK, I get no exotic hardware and everything is statically built. (No modules, the nvidia proprietary driver excepted)

BTW, I investigated quite a lot trying to understand exactly what (apart from a line in some obscure upstream's readme )makes that KV_MIN=2.6.39 requirement but just failed._________________

I can't get a single hvm DomU to start on gentoo. They all fail immediately or enter an infinite restart-loop if I don' t set the destroy option on reboot. Trying to boot from a physical cdrom-drive just fails a bit later, because it apparently first has to spin up the disc in order to not work. Nothing in the logs point to any errors, apart from shutting down with reason code 1 0x1.

Since the same domU-configuration works on xen4.2 in combination with fedora 18 and a 3.something linux kernel, I'm at a loss what' s going wrong. I've read some bug-reports mentioning the current udev-version in portage as the culprit for xen not functioning anymore. However this thread seems to suggest that some people do have xen working with a recent gentoo-sources kernel and udev. What's the trick?

Has anyone gotten xen to work with the current udev and gentoo-kernel, with safe cflags and gcc-4.7/4.6? If so, would you be so kind to share your settings?

Just to be sure my emerge --info is the following. Sorry for the huge wall of text, I don't know how to make it collapse on this forum like with the common spoiler option. Because of numerous gentoo based projects like an arcade-cocktail-cabinet this list is a lot messier than it ought to be, which is why I want to go the Xen-route.

I've switched to gcc-4.6 and changed the cflags to -O2 -pipe plus set march and mtune to bdver1 and reverted to Xen 4.2.1-r1 with those settings, just to be sure I also reinstalled udev and qemu with the same settings. So far no luck, I even tried using the custom-cflags useflag, to make sure it wasn't an issue with using march=native and the bulldozer architecture on gcc-4.6.

I'd like to switch entirely to xl, but that just fails without any meaningful warning message, even when running with the verbose option. (Any ideas how to get xl to spit out more info?) I was under the impression that if you don't start xend, xl should work as expected. xm with running xend now complains about missing vbd. My searches on the internet only gave me 2 possible causes for this error. The xen-wiki mentions missing support for the blkdev-backend in the kernel, which is compiled into my kernel.

The second cause was udev. Mostly mentioned in older posts about udevinfo being removed from udev or missing xen-rules in udev. The missing udevinfo should not be an issue for xen 4.2 and I've checked that I have two xen-rules entries in /lib64/udev/rules.d. Admittedly I wouldn't know if those entries are correct or not, just by looking at them.

Since your xen works, I guess I can rule out problems with xen itself or seabios. I suppose this only leaves xend and/or the udev-rules as the culprits. I haven't switched to eudev, because of a post by one of the gentoo-devs saying that eudev was only meant for running 2.6 kernels and should not be used with the 3.something kernels.

I'll try one last time without xend and clearing everything xen-related beforehand, but I very much doubt that will produce a different result.

Last edited by DoPlJoe on Tue Feb 05, 2013 1:23 pm; edited 2 times in total

It works!!!
I'm using gcc-4.7 and removed everything xend and all the extra cflags, removed all configs and made a new xl ones following the xl man-pages on the xen-site.

Thanks for taking the time to help me out, trying to match your setup as close as possible made it work for me.

Next up getting vga-passthrough to work not only for the amd videocard.

EDIT
I think I may have narrowed the issue down to gcc-4.7 and march=native not working, while using march and mtune bdver1 do work on my fx8120 cpu. Only discovered this by accident, when I set the cflags but forgot to change to gcc-4.6.